Fill 'er Up

With invoice-busting diesel prices, strategies to increase fuel economy are more valuable than ever. Here are six tips for saving fuel this spring:

THINK ABOUT FUEL economy as you select tractors and transmissions. Use a tractor that's large enough to pull the desired implement, but avoid using too large a machine.

“Tractors are designed to deliver the most energy per gallon of fuel when operated in higher power ranges,” says Roger Hoy, director of the Nebraska Tractor Test Lab at the University of Nebraska.

Hoy says tractors equipped with variable rate transmission technology, such as John Deere's (JD) infinitely variable transmissions (IVT) or AGCO's continuously variable transmissions (CVT) also offer excellent fuel economy because they automatically shift up or down based on power requirements. “If power is not needed, they will shift to a faster transmission ratio and reduce engine speed,” says Hoy.

SHIFT UP AND throttle back. Hoy says although IVT and CVT technology automatically perform gear and engine speed adjustments to enhance efficiency, operators can improve fuel economy by shifting up and throttling back whenever possible. Hoy says most tractors (even well matched to the job) are typically a tad too big for the implement, often needing to operate at only 50-80% of pulling capacity.

By shifting up a gear or two, engine speed can be reduced while providing adequate pulling power without losing ground speed. Hoy gives the example of a JD 8430 PST tested in the Nebraska lab last year. When the tractor was operated in 12th gear vs. 10th gear to pull a 10,012-lb. load (noted to be 75% of maximum pull power), fuel consumption decreased by 7.4% from 0.462 lbs./hp-hr. to 0.428 lbs./hp-hr., rpm went from 2,155 to 1,610.

“A lot of farmers want to see their tractor operate at 2,000 rpm (because that's the rated speed), but if you can run at 1,600 rpm and still get the job done you may save yourself some money,” says Hoy. Similar savings from shifting up and throttling back were shown with other brands and models. Results can be found at http://tractortestlab.unl.edu/testreports.htm.

MAKE SURE EQUIPMENT is properly ballasted. Many growers add weight for heavy fall tillage but fail to remove it before lighter springtime work, according to Roger Lewno, a tractor marketing and training manager for Case IH.

When tractors are ballasted too heavily, “more power is required to move the vehicle through the field and less is available to do work, so the result is less performance and increased fuel costs,” Lewno says.

On the other hand, if tractors are too light ? based on horsepower ? or if tires are over-inflated, more slippage occurs, translating into wasted fuel economy.

Chad Hogan, a JD product line manager for large row-crop tractors, says most tractors should weigh 120-125 lbs./PTO hp, given faster working speeds common today. But he warns that total weight is only one part of the equation; ballast must be properly distributed between front and rear axels depending on the type of drivetrain. “You need to use the right weight, at the right time and in the right place,” he explains.

CHECK TIRES AND tire pressure. “Growers routinely check oil and coolant but they often take the tires and wheels for granted,” says Hogan, who says wider tires are generally better than narrow ones when it comes to fuel savings. Check your tractor operator's manual (you can also find tire information on JD's ballast calculator) for recommended inflation levels for drivetrain and tire type. Pressures that are too low can lead to powerhop pitching and bouncing, but “if inflation is too high, you get increased slippage and decreased fuel efficiency,” Hogan says.

CONSIDER AUTO-STEER. Lewno says that most people think of improved planting and spraying accuracy as primary benefits of automatic guidance systems, but the impact of reducing overlap shouldn't be underestimated. Without auto-steer, Lewno says farmers often crowd their passes in the field to avoid skips, easily adding up to extra hours in the field due to overlap. “The smaller the tool, the bigger the savings,” says Lewno.

“Auto-steer can decrease overlap typically by 10-15%,” says Hogan.

USE THE BELLS and whistles and maintain equipment. Case IH's Magnum and Steiger tractors offer “performance instrumentation” that allows operators to monitor fuel consumption per hour or acre, wheel slippage, ground speed and engine power used so adjustments can be made as you go, says Lewno.

Lewno also reminds growers to set remote valve timers that control the tractor's hydraulic pump. “If the timers are not set properly, it may take 1-2% of the engine power to maintain the pump at high pressure,” he says. While that's not a huge draw, Lewno says, it's a fuel robber that can be avoided.

The cooling system must also be kept clean, including the radiator and engine and fuel filters. With heavy field dust, filters can easily become clogged, which means cooling fans must run more, says Hogan. “It can take 10% of the engine power just to run the fans,” he says.

Finally, be sure to give your employees clear directions and advice on how you want equipment operated and maintained in order to optimize fuel economy. With $3-plus/gal. diesel prices expected, that could mean money in the bank this spring.